package org.niux.aims.common.web;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;


/**
 * 用于动态生成验证码图像的Servlet.
 * 用户可以根据自己的喜好实现自己的Servlet。
 * @author CE
 *
 */
public class VerifyCodeServlet extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 7342844877456876447L;
	public static final String RANDOM_CODE_VERIFY = "RANDOM_CODE_VERIFY";
	
	/**
	 * Constructor of the object.
	 */
	public VerifyCodeServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to
	 * post.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// 取得一个1000-9999的随机数

		HttpSession session = request.getSession();
		// session.setAttribute("getImg",s);
		response.setContentType("image/gif");
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		int width = 60, height = 20;

		ServletOutputStream out = response.getOutputStream();
		BufferedImage image = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB); // 设置图片大小的
		Graphics gra = image.getGraphics();
		Random random = new Random();

		gra.setColor(getRandColor(200, 250)); // 设置背景色
		gra.fillRect(0, 0, width, height);

		gra.setColor(Color.black); // 设置字体色
		
		//设定字体
		gra.setFont(new Font("Times New Roman",Font.PLAIN,18));

		// gra.setFont(Font.);

		/*
		 * gra.setColor(new Color(0)); gra.drawRect(0,0,width-1,height-1);
		 */

		// 随机产生1００条干扰线，使图象中的认证码不易被其它程序探测到
		gra.setColor(getRandColor(160, 200));
		for (int i = 0; i < 100; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			gra.drawLine(x, y, x + xl, y + yl);
		}

		// 取随机产生的认证码(4位数字)
		String sRand = "";
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
			// 将认证码显示到图象中
			gra.setColor(new Color(20 + random.nextInt(110), 20 + random
					.nextInt(110), 20 + random.nextInt(110))); // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
			gra.drawString(rand, 13 * i + 6, 16);
		}
		
		session.setAttribute(RANDOM_CODE_VERIFY, sRand);
		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
		encoder.encode(image);
		out.close();

	}

	static Color getRandColor(int fc, int bc) { // 给定范围获得随机颜色
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	/**
	 * Initialization of the servlet. <br>
	 * 
	 * @throws ServletException
	 *             if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}
}
